آیا برون سپاری و درآمدهای رانندگان از طریق غیر از حمل و نقل هوایی ، در بهره وری فرودگاه های اسپانیایی، اهمیت دارد؟

This paper evaluates the influence of contracting out, or outsourcing, certain airport services and of commercial diversification strategy. Although most of the effort is being put towards applying non-parametric techniques in airport efficiency studies, we have chosen parametric methodology. We use a distance function, as it has known advantages. The findings show the positive contribution of outsourcing and non-aeronautical revenues on the efficiency of the Spanish airports' network.

Measurement of an airport's efficiency is important in ensuring its efficiency. Evaluating the efficiency of airports is, however, difficult. Factors such as the ownership structure, political constraints and the economic structure of the region the airport is located in make the evaluation of the efficiency difficult. Changes in airport ownership patterns have shifted managerial attention towards commercial returns and non-core airport activities. Oum et al. (2006), for example, found evidence that business diversification helps airports achieve higher operating efficiency, because of complementary demands between aeronautical and commercial services. However, they had limited data on outsourcing activities and this may explain why outsourcing had no relationship with efficiency. Low and Tang (2006) found outsourcing to be a substitute for both labour and capital, and could be an alternative to investment. Spain's airport network was centrally managed until the beginning of the 1990s after which airport authorities were allowed to exploit their facilities on a commercial basis, to improve efficiency. The result was that some core airport activities were outsourced to exploit the complementary demand between aeronautical and commercial services. Here we evaluate the influence of contracting out (outsourcing) and commercial diversification strategy on the technical efficiency of airports.

The paper estimates a distance function to analyze and explain Spanish airport efficiency. We consider that the multioutput parametric stochastic distance function outperforms the previous methodologies used in most airport efficiency and performance studies. It has valuable advantages, when analysing the efficiency of regulated industries like airports. Moreover, the empirical evidence found in this study was similar to those in the literature reviewed. On the one hand, airports that outsource some services are expected to have a higher efficiency level than those that do not. The reason is that they are able to focus more attention on their core services and thus improve their competence. Spanish airports that outsource their peripheral services show an above average level of efficiency. Consequently, Spanish airport managers should be free to outsource some terminal services to specialized firms. On the other hand, Spanish airports with well-developed commercial activities are also more efficient than those that do not diversify revenue sources. However, we have to say that this effect may be associated to the airport's international passenger volume airport.